On Fat Tuesday, Mardi Gras in New Orleans, a ferry (the "Sen. Alvin T. Stumpf") is carrying several hundred U.S. Navy sailors and their families from the Algiers dock to a celebration, when it explodes and sinks into the river, killing at least 543 on board. Agent Doug Carlin from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is sent to investigate the explosion and discovers evidence that the attack was committed by a domestic terrorist. On arrival at the scene he hears his phone ringing which he discovers isn't his ,coming from a body bag nearby.He then meets with the investigating police officers and FBI Agent Paul Pryzwarra, and informs them of his findings. Back at his office, Doug learns about a charred body pulled from the river, that of a Claire Kuchever. However, unlike the other bodies found in the river, this one was discovered to have been killed before the explosion.